Experience from a telestroke network reveal metrics that help pinpoint where changes can be made to speed up processes of care.

 

Long transfer times between community-based ‘spoke’ hospitals and large, tertiary ‘hub’ hospitals reduce the likelihood of receiving endovascular thrombectomy, one study shows.

A patient’s chance of having thrombectomy decreased by 1% for each additional minute of transfer time over 60 minutes, with the most pronounced transfer delays occurring at night.

“In terms of treatment effect, [endovascular thrombectomy] is one of the most powerful therapies in the history of medicine,” Thabele M. Leslie-Mazwi, MD (Massachusetts General Hospital, Boston, MA), the study’s senior author, told Neurovascular Exchange. “We need to improve how we get it to patients. It is very important that stroke patients get moved to centers that can evaluate them for treatment as quickly as possible.”

Leslie-Mazwi and colleagues conducted a retrospective study to look at how transfer time in a hub-and-spoke telestroke network affected outcomes among patients with suspected large vessel occlusions. The study, published online April 30, 2018, ahead of print in Stroke, included 234 patients transferred to a single hub hospital from 2011 to 2015.

All patients had onset within 12 hours of arrival at the hub hospital and had a National Institutes of Health Stroke Scale score of 6 or greater. About half were transferred to the hub via ambulance (51%) and half via helicopter (49%). Twenty-seven percent underwent endovascular therapy, with about one-third (37%) achieving a modified Rankin Scale score of 0-2 by 90 days.

Ideal transfer times were calculated using an algorithm that accounted for distance to the hub, traffic, and telestroke consult time, treatment and stabilization of the patient, and preparation for transport. The median actual transfer time was 30 minutes longer than the median ideal transfer time (132 vs 102 minutes). In logistic regression analysis, longer transfer time was associated with decreased odds of thrombectomy (OR 0.990; P = 0.003).

Patients with transfer times within 60 minutes had a 44% chance of undergoing thrombectomy, with decreases in that percentage for each additional minute of transfer time.

Night transfer between 6 PM and 6 AM was associated with delays of about 20 minutes longer than transfers that occurred during the day. Intravenous tissue-type plasminogen activator (tPA) delivery at the spoke hospital was not associated with any significant delay, nor was being treated on a weekend.

Algorithm May Help Improve Processes of Care

Lead study author Robert W. Regenhardt, MD, PhD (Massachusetts General Hospital, Boston, MA), told Neurovascular Exchange that the situation is a common one, since patients with large vessel occlusions often need to be transferred from a hospital without endovascular thrombectomy capabilities.

 “Our paper proposes an algorithm for individualizing transfer metrics based on the geography of each spoke,” he added. It includes separate air and ground algorithms that account for activation time, geographic distance, and typical travel speeds to customize time metrics for each center with a referral network, he and colleagues explain in the paper.

“If you are having a stroke, night time is clearly not the right time, with an average transfer delay time of about 31 minutes compared with 14 minutes during the day,” Leslie-Mazwi said. “There should now be a focus on improving processes that are dependent on time of day. Overall, the goal is to make it easier for patients to get the care they need. Based on the results of this study, improving night-time transfers is low-hanging fruit.”

 


Sources:

Regenhardt RW, Mecca AP, Flavin SA, et al. Delays in the air or ground transfer of patients for endovascular thrombectomy. Stroke. 2018;Epub ahead of print.

 

Disclosures: